CYA = Zero

[chem geek]

If you truly don't have any CYA in the water (i.e. if the CYA test doesn't even get cloudy at all), then your chlorine is likely burning off to zero at some point during the day so the cloudiness could be a nascent algae bloom.

You have several options for adding CYA to your pool as follows:

1) You can buy Cyanuric Acid (CYA) directly and put it in a panty hose or sock you hang over the side of your pool in front of a return. This will have the CYA dissolve in a day or two instead of taking a week.

2) You can temporarily switch to using Trichlor slow-dissolving tablets/pucks as your source of chlorine, but they are very acidic so you will need to add pH Up / Arm & Hammer Super Washing Soda / Sodium Carbonate periodically. For every 1 ppm FC from Trichlor you get 0.6 ppm CYA. This is an inexpensive option when accounting for the price of both CYA and chlorine.

3) You can temporarily switch to using Dichlor granules which quickly dissolve. This is also an acidic source of chlorine (after chlorine gets used up), but not as much as Trichlor. For every 1 ppm FC from Dichlor you get 0.9 ppm CYA. This is a more expensive option, but is convenient.

4) You can use the Natural Chemistry product called Instant Pool Water Conditioner found here. This is essentially CYA in a different form that is fast-dissolving. It is more expensive than pure CYA in option #1, but is more convenient.

It is important to not add too much. Try and target 30 ppm CYA and see how that goes for you. You can always add more if the chlorine seems to be burning off quickly, but higher CYA levels require higher FC levels to compensate (see Ben's Best Guess CYA chart).

Richard